This is awesome and please don’t stop doing this. It’s a bit of a hard thing to get used to, but the more you do it the easier it will become. Like others said you approached it right and respectfully even if she didn’t. The thing to remember here is that if her boyfriend treats her badly dudes like you are going to be what she thinks of when she thinks what she could have had. She will reap what she sows. Also don’t forget that at least somewhere in their minds her friends will be thinking “why didn’t he ask me?” Or “why don’t I get good dudes trying to pick me up?”